1. Field of the Invention
The present invention relates in general to wireless information communication systems, and in particular to cordless telephones with integral telephone answering devices (TADs).
2. Description of the Prior Art
The present invention relates to telephone answering machines, but also to telephone functions now commonly available in personal computers equipped with voice/fax modems.
Heretofore, telephone answering devices and other voice messaging solutions, including computer implemented voice mail functions (hereinafter collectively referred to as “TAD”), could be answered by someone other than the intended called party. In other words, when a calling party attempting to reach a called party called the TAD, some other person could inadvertently pick up the telephone during the outgoing message (OGM) and interrupted the message recording process. Typically, the OGM would be interrupted so that the calling party and the answering party could speak to one another immediately without the noise and inconvenience of the OGM playing over their conversation, such as seen in US RE 33,507 issued to Hashimoto for cordless TADs or other methods related to conventional corded TADs such as seen in U.S. Pat. No. 4,451,707 issued to Hanscom. However, this was inconvenient for both the party answering the called parties' line and also inconvenient for the calling party, for a number of reasons.
In one case, the answering party would be then required to manually take a message from the calling party, which may lead to inaccuracies in the message being conveyed to the called party because of errors by the answering party in transcribing the message or due to message complexity. In another case, the calling party would then have to call the TAD again in order to record a complete message, in hopes that the call would not be again answered by the wrong person. Or in the case where the answering party returned the telephone to an on-hook condition in an attempt to return control to the TAD for message handling, the on-hook condition would be detected and the calling party would be disconnected from the TAD. Another problem occurs when the proper called party answers the telephone and interrupts the message handling of the TAD and does not have time to talk to the calling party.
In an attempt to alleviate the problem, Hashimoto U.S. Pat. No. 5,138,652 teaches the use of a line monitoring circuit that detects an initial off-hook condition by the answering party and measures a predetermined period of time (for example, 3 seconds) to see if an on-hook condition occurs within the predetermined period of time. The line monitoring circuit detects that the telephone has been taken off-hook by the answering party (as opposed to the intended called party) in response to the incoming call. Then, a timer is started to monitor for a subsequent detection of an on-hook condition by the answering party after it is discovered the call was answered in error. If the on-hook condition occurs within the predetermined time period, the TAD is then allowed to continue in completing the message process and a message from the calling party is recorded on tape or digital memory such as a memory IC or analog tape. The problem with this approach is that in the event the answering party takes longer than the predetermined time period to return the telephone to an on-hook condition, the TAD cannot be returned to take control of the message process.